It’s 1 a.m. on a January evening and strong winds are blowing through Santa Clara. A palm frond breaks loose and flies into a power line. Lights in nearby homes flicker and then go out. Customers begin reaching out to us to see if they are the only customer without power and when power will be restored. But what’s going on behind the scenes? While every power event is different, here’s a look inside a typical outage.
Operational Center: When the palm frond shorts out the line, a control operator at our operational center sees an alarm on the monitor; a short circuit “fault” has completely shut down a circuit covering multiple neighborhoods within the city. As a safety measure, the automatic response system does not attempt to restore power to the area until it can be inspected for damage and safety, and ultimately re-energized by our personnel.
The control operator immediately alerts managers, customer service, and dispatch. Shortly after the first alarm, a troubleshooter is sent out to begin tracing the problem. In a large outage like this, the customer service team begins posting to social media and they’re called in to start fielding calls from residents. Sometimes residents can provide information that helps pinpoint the exact location of the issue, which is often helpful after dark.
Distribution Substation: Still unaware of the exact cause, our substation electrician heads to the distribution substation nearest to the affected area to determine if the problem stems from the substation itself, or the distribution line that showed an alarm. The electrician identifies that the issue is within the distribution line and alerts the control operator, who directs the troubleshooter to begin inspecting the lines of the affected circuit.
Power Checkpoints: The troubleshooter inspects circuit indicators on checkpoints along power poles and in readily accessible underground vaults located every few blocks, following the flashing warning signals along the circuit. When the troubleshooter finds a checkpoint with normal, non-flashing indicator, it means the problem is between that check point and the previous one inspected. Many times, the troubleshooter will begin isolating the problem area and restore power to residents in cleared zones.
Issue Area: The troubleshooter soon finds the palm frond that has landed below the power lines. Fortunately, the power lines have not been damaged. However, the palm frond has been scorched by 12,000 volts of electricity. The crew informs the operator that all is clear. The electrician at the substation resets the sensors, initiates all safety checks, and enables power to flow back through the circuit.
Nearby Homes: The cause and location of the outage determines the time to restore power to customers, and it is important for our staff to conduct safety inspections before returning power to affected circuits. If the problem section of the line can be isolated, many customers can have power restored just minutes after the problem is identified.
Our team works hard to ensure minimal power disruption, but power restoration times vary and some occurrences are beyond our control. When an unexpected power outage like this occurs, we want you to be ready. To prepare your home for when the lights do go out, check out our power outage preparation tips.